In recent years, cameras are becoming more convenient with the increase in functions offered by these cameras. User's needs are shifting towards imaging techniques supported by camera functions. One of such imaging techniques is the follow shot. Follow shot refers to capturing a picture by pointing the lens at a subject whose image is to be kept in a specific position within the picture, and moving the camera in accordance with the movement of the subject while the shutter is open so that the position of the subject does not shift. In a follow shot picture, the subject appears still and the background comes out blurred, with the degree of blurring depending on the amount of camera movement during the exposure.
As a result, in a follow shot picture, it is possible to express the sense of speed of a fast-moving subject such as an airplane during take-off and landing or low-level flight, or a moving train, automobile, or bike.
In the case where a user takes a follow shot by moving the camera by hand, there are many instances where even the image of the subject becomes blurred due to significant hand shaking. In particular, follow shot photography is a difficult imaging technique when the user is not skilled at hand-held photography. Even when a follow shot is taken using equipment such as a monopod or tripod, there are cases where the image of the subject is blurred in a direction that is different from the direction in which the subject is moving.
Conventionally, methods of performing blur correction of follow shot pictures have been presented (for example, see Patent Literature 1 (PTL 1)). FIG. 1 is a block diagram showing a conventional imaging device disclosed in PTL 1.
In FIG. 1, the imaging device includes an imaging unit 11, a control system unit 12, a cause information storage unit 13, a detection unit 14, a processing unit 15, and a recording unit 16. The imaging unit 11 captures a picture. The control system unit 12 drives the imaging unit 11. The cause information storage unit 13 stores known change cause information (for example, aberration of the photographic optical system, and so on) that causes image deterioration, and so on. The detection unit 14 is configured of an angular velocity sensor, and detects the change cause information which is the cause for change such as image deterioration, and so on. The processing unit 15 processes the picture captured by the imaging unit 11. The recording unit 16 records the picture that has been processed by the processing unit 15.
Furthermore, the processing unit 15 judges whether or not the captured picture is a follow shot-captured picture. Then, when the processing unit 15 judges that the captured picture is a follow shot-captured picture, the processing unit 15 performs blur correction using data resulting from the removal of the change cause information in the direction of the follow shot, from the change cause information stored in the cause information storage unit 13.
Furthermore, conventionally, methods of generating a follow shot picture from successively-captured pictures have been presented (for example, see Patent Literature 2 (PTL 2)). FIG. 2 is a block diagram showing a conventional imaging device disclosed in PTL 2.
In FIG. 2, the imaging device includes an imaging unit 21, a background acquisition unit 22, a processing unit 23, and a synthesizing unit 24. The imaging unit 21 captures multiple frames including an image of a moving subject. The background acquisition unit 22 calculates the difference of images between the frames so as to remove the image of the moving subject from the frames. The processing unit 23 is capable of generating a picture having a blurred background by performing a blurring process on a picture from which the image of the subject has been removed. The synthesizing unit 24 generates a picture in which the background is blurred and the subject appears clearly, by superimposing the image of the subject onto the result of blurring process.